1. Field of the Invention
The present invention relates to a refrigerator, and more particularly to a refrigerator driving control apparatus and method thereof to control the rotation speed of an air blowing fan, thereby improving cooling efficiency and reducing power consumption.
2. Description of the Prior Art
In general, a refrigerator, as shown in FIG. 1, is provided with spaces divided by an intermediate member(20) into two, an upper space(30) for freezing food and a lower space(40) for refrigerating the food at storage containers, cold air circulating means(50) disposed at the rear portion of a freezing chamber(30) for compulsorily circulating air current, and a damper(60) installed on the rear wall of the cabinet(10) at a predetermined interval with a cold air discharge hole(61) and a cold air suction hole(62) for forming a cold air circulation route in which the cold air blown by the cold air circulating means(50) is guided and, at the same time, discharged upward and sucked downward the freezing chamber(30).
At this time, the cold air circulating means(50) comprises an air blowing fan motor(51) driven as power is applied, an air blowing fan(52) rotated as the air blowing motor(51) is driven, and a bracket(53) to fix the air blowing fan motor(51) on the cabinet(53).
A evaporator(70) is installed under the cold air circulating means(50) for repeatedly heat-exchanging the air at the freezing chamber(30) and refrigerating chamber(40) into cold air, a defrosting heater(80) installed under the evaporator(70) to be turned on and off for removing the frost formed at the surface of the evaporator(70), and a water drain hose(90) connected from the defrosting heater(80) along the rear wall of the cabinet(10) for discharging out the water during the defrosting operation.
An evaporating dish(110) is installed under the water drain hose(90) at the machine room(100) formed at the lower rear part of the cabinet(10) for collecting the water discharged along the water drain hose(90) and for vaporizing the collected water with the compressing heat of a compressor. The compressor(120) is installed under the evaporating dish(110) for compressing into a coolant of high temperature and high pressure, and a concentrator(130) is disposed at the rear outer surface of the cabinet(10) for condensing the compressed gas coolant of high temperature and high pressure by natural convection.
On the other hand, there are provided a first cold air pass(150) formed at a rear part of the intermediate member(20) at a predetermined interval on a cold air flow guiding plate(140) for discharging cold air heat-exchanged at the evaporator(70) toward the refrigerating chamber(40), a second cold air pass(160) formed at another rear part of the intermediate member(20) at a predetermined interval for passing the cold air of the refrigerating chamber40) through the evaporator(70), and a temperature control apparatus(170) assembled at the rear upper end of the refrigerating chamber(40) for controlling supply of the amount of the cold air discharged through the first cold air pass(150) to the refrigerating chamber(40) in a plurality of steps (for instance, strong cooling, weak cooling, etc.).
Unexplained numerals, 180 and 181, are respectively a freezing chamber door and a refrigerating chamber door hinged at the freezing chamber(30) and the refrigerating chamber(40) in an opening and closing manner, and 190 is a shelf member to put the food containers with selective vertical mobility.
Here, an air blowing control apparatus, as shown in FIG. 2, is to drive the air blowing fan motor(51) and to rotate the air blowing fan(52) including a relay driving element(53) for transmitting a predetermined level of alternating current voltage (VAC) input from a power source to the air blowing motor(51) as the relay(54) is turned on or off according to a control signal sent from a control unit (not shown).
Next, operational procedures of the refrigerator is described below. First of all, when the temperature at the freezing chamber(30) and the refrigerating chamber(40) is manually set with a temperature selection key (not shown), the chamber temperature is detected by a chamber temperature detecting unit (not shown). If the detected chamber temperature is higher than the set chamber temperature, the compressor(120) (not shown) is driven.
If the compressor(120) is driven, a coolant is compressed into the gas coolant of high temperature and high pressure, thereby vaporizing the defrosted water collected at the evaporating dish(110) as passing through the condenser (not shown). The coolant passed through the concentrator(130) is cooled and liquefied into the liquid coolant of low temperature and high pressure as the coolant is heat-exchanged with outside air in natural convection or compulsory convection.
The liquid coolant of low temperature and high pressure is changed into the frosty coolant of low temperature and high pressure which is easy to be vaporized as it is passed through a capillary tube (not shown) where the coolant is expanded to reach vaporization pressure. Then, the frosty coolant is infused into the evaporator(70).
Accordingly, the frosty coolant of low temperature and high pressure is passed through a plurality of pipes of the evaporator(70) to be evaporated to get the chamber air heat-exchanged into cold air, and the gas coolant of low temperature and low pressure cooled at the evaporator(70) is sucked into the compressor(120). The aforementioned cooling cycle is repeatedly performed.
At this time, the control unit discriminates whether the chamber temperature detected by the chamber temperature detecting unit is higher than the chamber temperature set by an user. If so, the control unit sends a control signal to turn on the air blowing fan(52) to the air blowing driving element(53). Then, a relay driving element(53) starts the operation of a relay(154) to supply a predetermined level of alternating current voltage (VAC) input from outside to the air blowing fan motor(51).
The air fan motor(51) is subsequently driven to rotate at high speed (for instance, about 3000 rpm) the air blowing fan(52) connected to a rotating shaft. The air blowing fan(52) rotated at high speed discharges the cold air heat-exchanged at the evaporator(70) through the cold air discharging hole(61) and the first cold air pass(150), thereby cooling the freezing chamber(30) and the refrigerating chamber(40).
Here, the temperature of the evaporator(70) is relatively high at an initial operation stage of the compressor(120), where the evaporator(70) does not generate much cold air.
However, there is a problem of the conventional refrigerator in that the air blowing fan(52) is rotated at high speed at an initial operation stage of the compressor(120), so that hot air is blown from the evaporator(70) into the chambers, causing to consume in cooling unnecessary power the chamber temperature to a chamber temperature set by the user.